Adhesive composition

ABSTRACT

The present invention relates to a composition which comprises at least one triblock copolymer, one terpene resin, one liquid component and one ethylene-vinyl acetate copolymer, and also to a process for preparing this composition, and to its use.

BACKGROUND OF THE INVENTION

The present invention relates to a composition which comprises at leastone triblock copolymer, one terpene resin, oneliquid component and oneethylene-vinyl acetate copolymer, and also to a process for preparingthis composition, to its use and to a multilayer product comprising thecomposition of the invention.

The adhesives industry is looking for adhesives which adhere not only topolar articles but in particular to apolar articles as well.

U.S. Pat. No. 4,412,030 discloses hotmelt pressure-sensitive adhesives(hmPSAs) which are composed of a special resin based on phenyl andstyrene and/or α-methyl styrene, a triblock diene copolymer and anethylene-vinyl acetate copolymer. The latter has vinyl acetate contentsof up to a maximium of 45% by weight.

EP-A 0 934 990 discloses a hotmelt adhesive composition and its use forbonding paper at 121° C. Among its constituents the claimed compositionincludes an ethylene-vinyl acetate copolymer having a vinyl acetatecontent of 40% by weight and a melt flow index (“MFI”) of 1000. For theuse of this composition on all substrates and articles, the temperaturerange is unsuitable.

Pressure-sensitive adhesive (PSA) compositions for polyolefin surfacesare disclosed in EP-A 0 822 967. They comprise solution-polymerizedacrylates with chlorinated polyolefins and hydrocarbon tackifiers.

U.S. Pat. No. 4,357,459 describes a styrene resin which is modified byFriedel-Crafts reaction and which can be reacted together with acrylatesor ethylene-vinyl acetate copolymers as a hotmelt adhesive (hm) or as apressure-sensitive adhesive (PSA). Ethylene-vinyl acetates having a lowvinyl acetate content are used.

JP-A 2000 142 650 mentions a hotmelt adhesive (hma) which is based onethylene-vinyl acetate copolymers and is applied to moving objects at70° C.

The adhesive composition in JP-A 2000 137 438 is based on anethylene-vinyl acetate copolymer prepared so as to be detachable fromglass surfaces.

WO 00/27942 describes a paper label comprising ethylene-vinyl acetatecopolymer in an adhesive bond. This bond is generally unsuitable forvery smooth surfaces such as plastics.

In product information literature from Kuraray (LIR TechnicalInformation 1998,9 (1,000), p. 20, Kuraray Europe GmbH, Schiess-Strasse68, 40549 Dusseldorf, Germany) hotmelt adhesive mixtures are disclosedwhich differ from the present invention only in the vinyl acetatecontent of the ethylene-vinyl acetate copolymers used. The product withan increased vinyl acetate content of 40% by weight shows no increase intack over a vinyl acetate content of 28% by weight. For the product withthe increased vinyl acetate content it is possible to observe pooreradhesion to PE than for the product with the lower vinyl acetatecontent.

The state of the art presents a variety of adhesives which are tailoredto the particular material on which they are used but which do notadhere to smooth, relatively-polar and also apolar surfaces ofthermoplastics.

The object of the present invention is, therefore, to provide acomposition which adheres both to polar and to apolar surfaces ofthermoplastics and which allows an adhesive for thermoplastic surfacesto be provided.

DESCRIPTION OF THE INVENTION

The above object is achieved by means of a composition comprising:

a) from 10% by weight of 50% by weight of a triblock copolymer of theformula (I)

ABA,  (I)

 where

A is a block containing repeating units derived from styrene orsubstituted styrene and

B is a block containing repeating units derived from one or moredifferent dienes and the fraction of repeating units derived fromstyrene or substituted styrene in the two A blocks is in total from 10to 40% by weight,

b) from 10% by weight to 60% by weight of an alicyclic terpene resin,

c) from 10% by weight to 40% by weight of a component which is liquid at20° C. and is selected from the group consisting of a diene polymer, apoly-α-olefin, a refined mineral oil fraction comprising saturatedaliphatic hydrocarbons and mixtures thereof,

d) from 10% by weight to 40% by weight of an ethylene-vinyl acetatecopolymer whose vinyl acetate content is more than 40% by weight, and

e) from 0 to 30% by weight of further additives.

In the composition of the invention the MFI of the ethylene-vinylacetate copolymer used, measured in accordance with DIN 53 735 at 190°C. under a load of 2.16 kg, is preferably below 25.

For the alicyclic terpene resins of the composition of the invention itis advantageous to use terpenes which have an R&B point in the rangefrom 80 to 150° C.

In the composition according to the invention refined mineral oilfractions preferably having a melt viscosity of a maximum of 10,000poise at 38° C., are preferred for the component which is liquid at 20°C.

In the case of the present composition, preference is given to a vinylacetate content in the ethylene-vinyl acetate copolymer of more than 50%by weight.

The commixing of the constituents is the preferred process for preparingthe composition of the invention.

The present composition is preferably used as an adhesive.

The present composition is preferably employed for bonding labels, forbonding films in the packaging industry, and in the constructionindustry.

Preference is given to multilayer products which comprise thecomposition of the invention.

The composition of the invention is used with advantage as an adhesive.This adhesive, even at relatively low temperatures, exhibits a high bondstrength and good adhesion to polar substrates such as polyesters,polycarbonates, polyamides, ABS etc. At the same time it exhibits goodadhesion to relatively apolar thermoplastics as well. This relates inparticular to polyolefins. Moreover, while being suitable at the sametime for use as PSAs, these adhesive compounds also exhibit typicalproperties, of hotmelt adhesives (hm). One typical properties of hotmeltadhesives (hm) is that they become liquid at temperatures in the range≧150° C., so allowing application via pumps and nozzles. The typicalproperty of the PSA is that at just 20° C. the PSA has a tack sufficientto allow application.

Under the customary conditions the composition of the invention is waterresistant, because hydrolysis does not occur in the presence ofmoisture. Unlike polyesters and polyurethanes, for example, the mainchain of the ethylene-vinyl acetate copolymer is not attacked. Theethylene-vinyl acetate copolymer of the composition of the inventionmakes it easier to mix in polar components, since the ethylene-vinylacetate copolymer contributes increased polarity and hydrophilicity andso allows better interaction in particular with wash waters.

The composition of the invention contains advantageously from 10 to 50%by weight of a triblock copolymer. Preference is given to from 20 to 40%by weight of the triblock copolymer.

The triblock copolymer of the composition of the invention is preferablya tricopolymer of the formula ABA, in which A is a block whichpreferably contains repeating units of styrene or substituted styrenes.

Substituted styrenes are known and include such materials asalkyl-substituted styrenes. One preferred substituted styrene isα-methylstyrene.

The B block of the triblock copolymer of the composition of theinvention preferably contains repeating units derived from one or moredifferent dienes.

The dienes used in the B block of the triblock copolymer are the dienesknown to the person skilled in the art, preferably butadiene andisoprene or mixtures thereof.

The B block of the triblock copolymer may also be partly or fullyhydrogenated. In this case it is preferred to use ethylene-butyleneand/or ethylene-propylene blocks.

It is also possible, in addition to linear block copolymers, to useproducts with a branched and star-shaped structure, as described, forexample, in EP-A 0 798 358.

These triblock copolymers provide for a sufficiently high force ofcohesion and a partly elastic behaviour of the composition of theinvention. They make it possible for even liquid components to beincorporated readily into the composition of the invention.

The composition of the invention advantageously contains from 10 to 60%by weight of an alicyclic terpene resin. Preference is given to from 20to 50% by weight of the alicyclic terpene resin.

The alicyclic terpene resins of the composition of the invention areformed preferably by Friedel-Crafts polymerisation of appropriatemineral oil cracking fractions. These mineral oil cracking fractionspreferably contain α- or β-pinene, dipentene or limonene. Thepolymerisation of these monomers is preferably conducted cationicallywith initiation by Friedel-Crafts catalysts.

The alicyclic terpene resins of the composition of the invention are tobe understood as including copolymers of the terpenes, especially α- andβ-pinene, and also limonene and other monomers.

It is preferred to use alicyclic terpene resins with a low level ofaromatics. In this way it is possible to avoid instances of productdiscoloration.

The alicyclic terpene resins used have an R&B point (Ring & Ball point,determinable in accordance with ASTM D-36-70, using, for example, aWalter Herzog R&B apparatus, model MC-735) which is preferably in therange from 80 to 160° C.

The alicyclic terpene resins of the composition of the inventionpreferably have a viscosity in the range from 500 mPas to 10 000 mPasafter melting.

The composition of the invention advantageously contains from 5 to 40%by weight of a component which is liquid at 20° C. Preference is givento 10 to 30% by weight of the liquid component. The component of thecomposition of the invention that is liquid at 20° C. preferablycomprises diene polymers or a refined mineral oil fraction whichcomprises saturated, aliphatic hydrocarbons.

The diene polymers of this liquid component of the composition of theinvention are customary diene polymers of low molecular mass, especiallyn-polybutadiene, n-polyisoprene, and low molecular masspolyisobutylenes. It is also possible to use poly-α-olefins which areliquid at 20° C., especially polypropylene, polybutylene andhydrogenated polybutadienes, as the liquid component.

The mineral oil fractions of the liquid component of the composition ofthe invention are advantageously paraffinic or naphthene-based mineraloils. These mineral oils include preferably linear, preferably branchedor cyclic aliphatics having C₅ to C₅₀ atoms. Preference is given tothose linear, branched or cyclic aliphatics having C₅ to C₄₀ atoms.

Among the cyclic aliphatics, preference is given to the fractions whichare composed of cyclopentanes and cyclohexanes or the alkylatedderivatives thereof.

The composition of the invention contains advantageously from 10 to 40%by weight of an ethylene-vinyl acetate copolymer. Preference is given tofrom 15 to 30% by weight of the ethylene-vinyl acetate copolymer.

The ethylene-vinyl acetate copolymers of the composition of theinvention preferably possess a vinyl acetate content of more than 50% byweight. With preference the vinyl acetate content of the ethylene-vinylacetate copolymer is situated in the range from 60 to 85% by weight. Itis preferred to use an ethylene-vinyl acetate copolymer having an MFI inthe range from 3 to 20, measured in accordance with DIN 53 735 at 190°C. under a load of 2.16 kg.

The ethylene-vinyl acetate copolymer is extraordinarily resistant toageing effects which are triggered by heat, oxygen, ozone and light

The composition of the invention advantageously contains from 0 to 30%by weight of further additives. The composition of the inventionpreferably contains from 0 to 15% by weight of further additives.

As further additives for the composition of the invention it ispreferred to use hydrophilic components as described in JP-A 11 224 052.These hydrophilic components may in particular be surfactants and resinacids, but also copolymers with acid function such as ethylene-acrylicacid copolymers. The detachability of the labels, films, etc. from thesubstrates to which they are adhered may be optimised by way of thesehydrophilic components.

For the purpose of achieving high shear strengths at high temperatures,the composition may also be crosslinked following application.Crosslinking of this kind is possible by means of electron beams or byUV radiation and is especially suitable for thin layers.

The extent of crosslinking must be controlled well in order not to losetoo much tack.

Crosslinking with electron beams is especially advantageously withcompositions of the invention, since the ethylene-vinyl acetatecopolymer with a vinyl acetate content ≧50% by weight which they containis particularly easy to crosslink; that is, can be crosslinked with lowradiation doses. It suffers virtually no loss in its tack, while thecohesive forces increase.

The compositions of the invention are designated hotmelt adhesives (hm)because they must be mixed in a melting operation. The tacky, elasticmasses obtained have a tack in the range from 0.5 to 1.0 N/mm² even at20° C. and can therefore be regarded as being PSAs.

Solvent-free application to substrates or films, including releaseliners, can be carried out by way of corresponding applicators such asflat dies or blade applicators at temperatures in the range of 140-170°C.

The composition of the invention is employed advantageously for bondinglabels. By way of labels, a very wide variety of substances can bebonded to a variety of materials. As labels it is preferred to choosethose made of paper.

The materials to which bonding is to take place are customarythermoplastics, preferably polyesters, polycarbonates, polyamides andABS, but also polyolefins, especially polyethylene and polypropylene.

The composition of the invention can also be used in films in thepackaging sector.

Furthermore, it is possible to use the composition of the invention toeffect temporary or permanent fixing of film materials such aslow-density polyethylene (LDPE), ethylene-vinyl acetate, etc., insectors including, for example, the construction sector.

Depending on the field of use it is advantageous to select the othercomponents of the composition of the invention that are to be used,besides the ethylene-vinyl acetate copolymer, in accordance with theirstability with respect to ageing and weathering.

Preference is given to hydrogenated dienes as the B block in thetriblock copolymer and to hydrogenated low molecular mass dienes as theliquid component of the composition of the invention in order to ensurebetter ageing and weathering.

EXAMPLES

Materials Used

VA27: An ethylene-vinyl acetate copolymer having a vinyl acetate contentof 27% by weight, a density of 0.952 g/cm3, an MFI (melt flow index) of3 (measured in accordance with ASTM D 1238) and a melting point of 71°C. (Escorene® UL 00328 from Exxon).

VA68: An ethylene-vinyl acetate copolymer having a vinyl acetate contentof 68% by weight, a density of 1.08 g/cm3, an MFI of 30 (DIN 53 735 at190° C. and 2.16 kg); the product has no melting point and is completelyamorphous (VP KA 8896 from Bayer AG, Leverkusen).

VA80: An ethylene-vinyl acetate copolymer having a vinyl acetate contentof 80% by weight, a density of 1.12 g/cm3, an MFI of 5 (DIN 53 735 at190° C. and 2.16 kg); the product has no melting point and is completelyamorphous (Levamelt® 800 from Bayer AG, Leverkusen).

Kraton® D-1161 NU: A triblock copolymer (SIS (styrene-isoprene-styrene))having a styrene content of 15% by weight, a specified molar weight offrom 207 to 237 kg/mol and a melt index of 12 (measured in accordancewith ISO 1133 at 200° C. and 5 kg load) (from Kraton Polymers).

LIR-30: A polyisoprene which is liquid at 20° C. and has a specifiedmolar weight of 29 g/mol and a viscosity of 740 poise (38° C.) (fromKuraray).

Resin P×1000: An alicyclic terpene resin having a softening point of100° C. (from Yasuhara Chemicals).

Vulkanox® BKF: A phenolic antioxidant:2,2′-methylene-bis(4-methyl-6-tert-butylphenol) (from Bayer AG,Leverkusen).

Mixture Preparation

Compositions were produced in accordance with the following formula:Resin P×1000 was melted and after 2 minutes the ethylene-vinyl acetatecopolymer was added. After one minute Kraton D-1161 NU and, finally,after a further minute Vulkanox® BKF was added. Mixing was continued for30 minutes in order to ensure that the components were homogeneouslymixed.

Then the LIR-30 was added slowly and the mixture was stirred for afurther 10 to 15 minutes. The cooling was then switched off and, after10 minutes, the mixture, which had become somewhat more viscous, wasremoved.

TABLE 1 Amounts data of the composition (hm mixture) 1,2 and 3 Figuresin parts, 1 part = 0.62 g based on 100 parts of polymer, polymer meaningthe composition of VA, LIR-30 and Kraton ® D-1161 N. ComparativeInventive Inventive Components 1 2 3 P x 1000 60 60 60 VA27 30 VA68 30VA80 30 Kraton ® D-1161 40 40 40 NU Vulkanox ® BKF  1  1  1 LIR-30 30 3030 Appearance of grey, slightly transparent white white the mixtureCloud point coalesces at still slightly Still slightly (Kofler bench)230-250° C., from cloudy at cloudy at 230° C. only slightly 260° C. 260°C. cloudy, at 250° C. completely clear

As compared with the state of the art, compositions having a vinylacetate content well above 40% by weight were attained and then,surprisingly, the advantageous results below were achieved.

Tack Investigations on the Composition

The substrates were cut from the respective material in the form ofcircular test specimens having a diameter of 8 millimetres and werebonded to stainless steel dies using quick-setting cyanoacrylamideadhesive.

The substrates were as follows:

ABS Polymer Plates of Novodur® P2L-AT from Bayer AG, Leverkusen

PET polymer: Plates of Guttagliss Solair Extra made of Polyclear forgreenhouses

Wood: Glued wood with topmost beechwood lamination, adjusted to fireprotection class B1

LDPE film: Standard construction film 80 μm

Glass: Standard glass

Polycarbonate: Plates of Makrolon® 1143 from Bayer AG, Leverkusen,surface not treated

An LDPE film (adhesive backing) was coated using a 400 μm doctor bladewith a solution of a composition and was dried overnight in air. Thefilm thickness after drying was approximately 50 μm. The solvent was amixture of toluene, ethyl acetate and methanol in a ratio of 50:30:20parts by volume. This coated LDPE film was then bonded with acyanoacrylate, adhesive to an aluminium panel which served as samplesupport. This application from solution was used as the applicationtechnique for experiments, owing to the greater ease of handling of thecomposition.

Measurement Procedure

Description of the tack measurement instrument:

The measurement area consists of an underlay on which there is the LDPEfilm coated with the composition of the invention. The measuringinstrument is composed of a measuring die covered with a circularplatelet of the substrate. Die and substrate platelet are firmly bondedto one another. The die can then be positioned by robot freely on theadhesive film of the underlay with a defined contact force for a definedcontact time, before the force of removal required to raise the die isdetermined with the means of a load cell.

The measurements were carried out with the tack measuring instrument at20° C. 5 individual measurements were carried out on each batch, in eachcase against all of the samples. Contact was made with a pressure ofp=10 bar for a period of 10 seconds. After this contact time, theassembly was separated at a removal rate of 2 mm/s.

Values Obtained

TABLE 2 Hotmelt adhesive 1 Hotmelt adhesive 2 Hotmelt adhesive 3 TackSeparation Separation Separation N/ energy Tack energy Tack energy mm²N/mm² N/mm² N/mm² N/mm² N/mm² Makrolon 0.50 0.133 0.50 0.108 0.68 0.188Novodur 0.55 0.128 0.44 0.134 0.65 0.278 Wood 0.46 0.110 0.32 0.102 0.560.281 PET 0.38 0.082 0.42 0.085 0.52 0.232 LDPE 0.77 0.318 0.53 0.1800.60 0.337 Glass 0.75 0.160 0.78 0.154 0.92 0.235

Roller Peel Tests

In addition, peel tests were conducted in these tests, various substratefilms (PC, ABS, PET, LDPE) or substrate plates (wood, metal, glass) werecoated with the composition by the solution process, as described forthe tack measurements, and laminated to an LDPE film and also to aTeflon film. This construction was then used for determining the peelforce at 90°, with the maximum and the average force being determined ineach case. The values from the Teflon film served as a reference for theadhesion to a material of relatively low surface forces.

Performance of the Measurement:

TABLE 3 Results of the 90° roller peel tests Peel rate = 1.67 mm/s [N]hm 1 hm 2 hm 3 LDPE/PC F-max 2.42 1.26 2.49 F-average 1.52 0.93 1.70Teflon/PC F-max 1.29 1.90 2.06 F-average 0.81 1.40 1.57 LDPE/ABS F-max2.08 1.25 2.79 F-average 1.19 0.86 1.87 Teflon/ABS F-max 0.91 1.48 1.93F-average 0.50 1.04 1.47 LDPE/PET F-max 1.98 1.26 3.27 F-average 1.240.93 1.99 Teflon/PET F-max 1.13 1.27 1.82 F-average 0.46 0.91 1.29LDPE/LDPE F-max 0.85 1.32 3.52 F-average 0.51 0.67 2.31 Teflon/LDPEF-max 2.16 0.94 1.86 F-average 1.24 0.54 1.01 LDPE/Metal F-max 2.25 2.173.18 F-average 1.19 1.51 2.16 Teflon/metal F-max 0.83 1.83 2.17F-average 0.40 1.20 1.49 LDPE/glass F-max 1.68 1.69 2.87 F-average 1.171.18 1.70 Teflon/glass F-max 1.26 1.37 1.83 F-average 0.87 0.97 1.14LDPE/wood F-max 1.36 1.86 F-average 0.72 0.97 Teflon/wood F-max 0.64F-average 0.27

Comparison of the Tack Measurements of the Compositions of the Inventionwith the Comparative Tests

Composition (hm) 1 possesses only moderate adhesion on the testsubstrates, with the exception of LDPE. The latter can be explained bythe relatively low polarity of the ethylene-vinyl acetate copolymerused, which produces better compatibility with the apolar LDPE.

In composition (hm) 2 an ethylene-vinyl acetate copolymer is used whichis likewise very polar with a vinyl acetate content of 68% by weight.This ethylene-vinyl acetate copolymer has a particularly high MFI and istherefore unable to make virtually any contribution to cohesivestrength.

The composition 2 (hm) therefore achieves values equal to those ofcomparative 1.

Composition (hm) 3 has the highest tack values in all cases, except inthe case of LDPE, and also the highest separation energies. In respectof the polar thermoplastic substrates such as polycarbonate, ABS andPET, markedly higher tack values and separation energies are achievedwith composition 4. Moreover, the best values are achieved on wood andglass as well.

The advantage of composition (hm) 3 is that markedly improved adhesivevalues are achieved on polar substrates while at the same time highvalues with respect to apolar thermoplastics such as LDPE are retained.

These effects are surprising since the compositions of the invention arestill multi-phase at the application temperatures chosen here and hencethe effect of the more polar formulation component ethylene-vinylacetate copolymer was not foreseeable.

Comparison of the Peel Tests of the Compositions of the Invention withthe Comparative Composition

The peel tests with Teflon film and various substrates essentiallyreproduce the adhesion forces between the composition and the Teflonfilm. They are a measure of the tack of the composition in thehorizontal direction. It is found that the values obtained for thecomposition (hm) 2 and 3 are higher in almost all cases than those forthe composition (hm) 1. With composition 2 high values are obtained,since it can be assumed that the high MFI and thus the low molar weightof the ethylene-vinyl acetate copolymer it contains leads to high tack.The values of composition 3 are even higher.

Only in the case of the LDPE film does composition (hm) 1 (comparative)display the highest values, with composition (hm) 3 giving at leastsimilar peel forces.

The peel tests with LDPE film and various substrates are influenced bothby adhesion forces and also cohesive forces of the composition.

The composition (hm) 3 yields high values on metal and glass assubstrate. Composition (hm) 2 here shows a similar behaviour to that ofcomposition (hm) 1. In the case of the measurements with thethermoplastic films (ABS, PET and LDPE) against LDPE, composition (hm) 3is more suitable. Only in the case of LDPE against PC do thecompositions (hm) 1 (comparative) and 3 show similar values.

In the case of the LDPE/LDPE construction, particularly high peel forcesare measured with composition (hm) 3, which were not to have beenexpected in the light of the tack values and the separation energies.

This was not to be expected because the ethylene-vinyl acetate copolymerof the invention, with a high vinyl acetate content, is particularlypolar and not very compatible with the apolar LDPE.

It can be stated that compositions of type 2 and 3 which contain a vinylacetate content of more than 40% by weight give values which in almostall cases are higher than those of the comparative tests. The targeteduse of the ethylene-vinyl acetate copolymers of high vinyl acetatecontent makes it possible to increase the adhesion on polar substratesin particular. The compositions of the invention can therefore beemployed on substrates of different polarity.

Although the invention has been described in detail in the foregoing forthe purpose of illustration, it is to be understood that such detail issolely for that purpose and that variations can be made therein by thoseskilled in the art without departing from the spirit and scope of theinvention except as it may be limited by the claims.

What is claimed is:
 1. A composition comprising: a) from 10% by weightof 50% by weight of a triblock copolymer of the formula (I) ABA,  (I) where A is a block containing repeating units derived from styrene orsubstituted styrene and B is a block containing repeating units derivedfrom one or more different dienes and the fraction of repeating unitsderived from styrene or a styrene derivative in the two A blocks is intotal from 10 to 40% by weight, b) from 10% by weight to 60% by weightof an alicyclic terpene resin, c) from 10% by weight to 40% by weight ofa component which is liquid at 20° C., which is selected from the groupconsisting of selected from the group consisting of a diene polymer, apoly-α-olefin, a refined mineral oil fraction comprising saturatedaliphatic hydrocarbons and mixtures thereof, and d) from 10% by weightto 40% by weight of an ethylene-vinyl acetate copolymer whose vinylacetate content is more than 40% by weight.
 2. The composition of claim1, wherein the MFI value of the ethylene-vinyl acetate copolymer,measured in accordance with DIN 53 735 at a temperature of 190° C. undera load of 2.16 kg, is below
 25. 3. The composition of claim 1, whereinthe alicyclic terpene resin comprises terpenes having an R&B point inthe range from 80 to 150° C.
 4. The composition of claim 1, wherein thecomponent which is liquid at 20° C. is a diene polymer.
 5. Thecomposition of claim 1, wherein the vinyl acetate content in theethylene-vinyl acetate copolymer is more than 50% by weight.
 6. Aprocess for preparing the composition of claim 1, comprising mixing: a)from 10% by weight of 50% by weight of a triblock copolymer of theformula (I) ABA,  (I)  where A is a block containing repeating unitsderived from styrene or substituted styrene and B is a block containingrepeating units derived from one or more different dienes and thefraction of repeating units derived from styrene or a styrene derivativein the two A blocks is in total from 10 to 40% by weight, b) from 10% byweight to 60% by weight of an alicyclic terpene resin, c) from 10% byweight to 40% by weight of a component which is liquid at 20° C., whichis selected from the group consisting of selected from the groupconsisting of a diene polymer, a poly-α-olefin, a refined mineral oilfraction comprising saturated aliphatic hydrocarbons and mixturesthereof, and d) from 10% by weight to 40% by weight of an ethylene-vinylacetate copolymer whose vinyl acetate content is more than 40% byweight.